Ni-Resist

“Ni-Resist” is actually a trademarked name that has spread into common usage – in fact, these materials are more correctly known (in both research and in the context of national and international standards) as austenitic cast iron. These materials are heavily alloyed types of cast iron containing either nodular or flake graphite, and which contain more than 25% of non-ferrous alloying material, and are comparable to other highly alloyed materials such as stainless steels.

Their unique properties (especially for Ni-Resist D5S) allow their use in high-temperature applications up to 1000° C (1830° F). Their trademarked name of “Ni-Resist” is due to their high nickel content (typically greater than 20%), which ensures that the basic matrix remains austenitic. Ni-Resist cast iron materials exhibit a series of specific properties that make them interesting for a broad variety of applications, among them:

  • Corrosion-resistant for saline and alkaline environments (ocean/saltwater)
  • Resistant to oxidation/(mill)scale
  • High thermal stability
  • Thermal shock resistance
  • Highly ductile (high fracture strain)
  • Resistant to wear and tear and to erosion
  • Non-magnetic
  • Higher (EN-GJSA-XNiCr 20-2, commerically: D2) or lower (EN-GJSA-XNiSiCr 35-5-2, commerically: D5) thermal expansion coefficients as desired
temperature load of a ship engine (diesel engine) in exhaust manifold in waste-gas recirculation solved by SiMo alloyed spheroidal graphite cast iron.

TECHNICAL INFORMATION: NI-RESIST / AUSTENITIC CAST IRON

Ni-Resist represents a competitive alternative to thermally stable stainless steels; however, in comparison to such steels, Ni-Resist materials offer advantages in manufacturing which make them less expensive.

THIS MATERIAL GROUP IS CHARACTERIZED BY A WIDE SPECTRUM OF MECHANICAL PROPERTIES, WHICH ARE THEN DETERMINED BY THE HIGHLY VARIABLE NATURE OF THE ALLOYING ELEMENTS AND THE DIFFERING EFFECTS THE LATTER HAVE. WHILE THE STRENGTH (ROUGHLY 400 N/MM2) AND THE 0.2% OFFSET YIELD POINT (0.2% PLASTIC STRAIN, AROUND 210 N/MM2) IS EFFECTIVELY THE SAME FOR ALL TYPES, THE FRACTURE STRAIN CAN VARY FROM 7% FOR D2 MATERIAL, TO 10% FOR D5 OR AS HIGH AS 25% FOR EN-GJSA-XNIMN 23-4 (INFORMATION ABOUT THE SPECIFIC ALLOYS CAN BE FOUND IN THIS SECTION FOR DOWNLOAD).